Harlequin Bug

By Stephanie Rukowicz

The harlequin bug is a type of stink bug, much more colorful than the brown ones you might find around your house. An invasive species, it is a common insect pest of crucifers in the southern part of the U.S. but in recent years has been reported in PA as well.

2016 brought my first encounter with harlequin bugs. First eggs were sighted on kale around the same time I was noticing leaf miner damage to spinach and beet leaves (early May). At the time, I wasn’t sure what had laid the eggs, but noted their distinguished geometrical grouping and pattern.

 Uncapped (already hatched) eggs.

Side view of eggs, note black striping along side.

As the season progressed,the harlequin bugs made themselves known. Mostly laying on and inhabiting my kale plants, I attempted hand control by picking eggs and both adult and baby bugs, which helped but did not eliminate the population. I noticed as I pulled and destroyed severely infested plants that bugs and eggs could also be found on closely neighboring tomato plants. The warmer winter of 2015/2016 may have played a role in my new familiarity with this insect pest. Also, two plots in our garden use a radish cover crop, possibly providing a nice winter home for adult bugs.

Harlequin bugs on the underside of a collard leaf. Adult top left, youth middle right.

Later this season, I also spotted Harlequin bugs in the Parks and Rec vegetable garden at Columbus Square Park. Is this a new issue for South Philly? I wonder what next year’s gardening season will be like and if we need a more concentrated effort to control this pest population.

Collard leaf with damage from harlequin bugs,
browning and spotting. Also showing
concurrent damage from cabbage lopers
(holes and munching around leaf margins).

2014 Penn State Extension update:

“Early in the season populations and damage are often low and you may be tempted to ignore them. But, with two to three generations in a season, by the time fall crops begin to mature their numbers may be one hundred times as high, causing serious damage. Harlequin bugs reproduce quickly, developing from an egg to an adult in about 48 days. Adult males may live up to 25 days and females up to 41 days. During their adulthood they can mate repeatedly laying multiple egg masses of 12 eggs every 3 days. That means a single female can produce 164 eggs. My advice – don’t ignore harlequins bugs; put together a plan to keep their numbers low.”

Recommended cultural controls:

“Host-free periods without brassicas can help limit the population. Remember brassica cover crops, like forage radish, are known hosts. Harlequin can also feed and reproduce on wild weedy mustards (Shepherd’s purse, wild mustard, pepperweed), pigweed (Amaranthus spp.), lambsquarter (Chenopodium spp.). Keeping these weeds under control in fields and on field edges will limit habitat. Leftover crop residue in the field provides a protected host area for over-wintering adult harlequins. Remove or disk in residue to destroy overwintering sites. Trap crops have been recommended, but I would suggest that you need to rapidly kill the bugs in the trap crop, or destroy the trap crop and follow it with a host-free period, for this to work well. Plant an early crop of horseradish, mustard or kale and try to kill the harlequin bugs concentrated on this favorite host. One grower has successfully controlled harlequin by frequent vacuuming.”

Your Garden for 2017: Pests and Bio-controls

by Michelle L. Dauberman

Spring is right around the corner but it’s not too late to start planning your garden.  Part of your plan for 2017 may include weaning your garden off chemical pest control and you may have heard that bio-controls can help you in this endeavor but you’re not sure where to start.

Predatory insects (aka. beneficial insects) are a great place to start.  Yes, that’s right, beneficial insects.  Once you get over the fact that you actually want these bio-controls/insects in your garden you’re on your way to a healthy garden, better yields and a thriving ecosystem.

So, that’s all well and good but how do I attract the good guys to my garden?  Let’s start by planting groups of host plants like Achillea filipendulina (yarrow), Cosmos bipinnatus (cosmos), Solidago virgaurea (goldenrod) and Aster alpinus (aster).

It’s a good idea to plant these hosts in groups since it increases your odds of attracting/hosting predatory flies, lacewings, ladybugs, hover flies and parasitic wasps to and in your garden.  Once these predators are in your garden they will begin to prey on the undesirables like aphids, mealy bugs and a variety of insect larvae.

There are several other plants that you can utilize to your garden’s benefit beyond what’s mentioned in this post so don’t limit yourself to these plants and always experiment.  Another tip about host plants:  Stager your plants by flowering season.  If you stager them by season you’ll experience more uninterrupted bio-control coverage throughout your growing season.

For more information about beneficial insects check out these PSU Extension links:

http://extension.psu.edu/plants/gardening/news/2015/attracting-beneficial-insects

http://extension.psu.edu/pests/ipm/pestproblemsolver/house/home-garden/soil-plant-health/companion-plants

Winter Houseplant Woes

~ Jessica S. Herwick

When the weather makes outdoor gardening impossible, like many of you out there, I keep a small selection of edibles and ornamentals in the bay window of my Manayunk apartment, where I also cluster my kitchen herbs and houseplants to survive the winter. Indoor gardening requires a slightly different point of view.  You don’t have to worry about pests like squashbugs, finding their way into your zucchini patch.  But, there are a few stealthy intruders out there that can survive happily in both your outside and indoor garden projects, like mites, aphids and whiteflies – and if those whiteflies find their way into your houseplants, you don’t have the benefit of natural predators like birds swooping in to snack on the insects.  The management is all up to you. 

It happens to the best of us.  No matter how diligently you prepare your indoor garden, even the best of practices cannot prevent Mother Nature from creeping in and having her way one hundred percent of the time.  Especially inside.  I follow most of the basic preventative practices when growing indoors. Water less.  The plants aren’t as thirsty and the dry soil helps prevent a number of pests, molds and fungi from setting in. Feed less, and more naturally.  Avoid tap water.  Mist plants.  Keep an eye out for invaders.  Put out traps before you see a pest.  Most importantly, keep careful watch over your favorites!  Somehow, these insects and arachnids know which plants you hold most dear.  This year, they chose my 28-month-long project, the avocados I’ve been growing from discarded seed.  I have raised several and they function happily as houseplants, filtering the stuffy apartment air and keeping me occupied during snowstorms.

I thought my precautionary tasks had proven successful and was basking in my pest-free glory… until I saw the holes, the small ½” holes peeking through the soil surface of my largest and oldest of the avocado collection.  The holes were too perfect to have appeared as a result of watering, and I hadn’t been sticking my fingers in the soil, although that’s how it looked.  The plant stood strong, no visible signs of stress or damage.  I scratched my head, snapped a photo for future research, and went on about my task – being sure to pinch off the soil surface holes, hoping to force the pest to reemerge by closing off the tunnels. I should've known better, done more.  But I didn't, and I paid the price.

Two days later I had to pack up and leave town for a week.  The pest most definitely returned in my absence.  Arriving back home 6 days later, the holes were back and the avocado had been stripped.  EVERY SINGLE LEAF had either fallen or been clipped off.  This meant war.  I removed the plant in its entirety from the container to reveal dozens of well-fed beetle grubs enjoying the tender roots of what was a thriving 2 year old avocado sapling just a week ago.

Suddenly everything made sense! 


Remembering the Japanese Beetle, who made its way into my apartment back in August, I knew I'd been defeated.  I didn’t kill it because I’m a softie, and try not to kill every bug that intrudes in my home.  I didn’t chase it outside again, because I didn’t want to send a Japanese Beetle into my back yard garden, or my lawn to breed.  Instead, I chose to endure her buzzing and kept her captive in my entryway.  Little did I know that this perspicacious little beetle was cozying up under my avocado tree to lay her eggs, but the proof was in the larva.  Oh, so many larva!  I'm sorry, Mama Beetle.  I plucked them out and fed them to the birds. 

After a good rinsing, a new pot and some freshly purchased premixed potting medium, the avocado is now replanted and starting to show new signs of life.  I haven’t given up, especially not so close to Spring!  But it’s going to be an uphill battle. 

Although you may not be able to prevent a sneaky
beetle from laying her eggs in your plantlings, there are a few tricks you can make at home and keep on hand to manage pests that creep into your houseplants from the garden, back porch or that hole in the window screen you’ve been meaning to fix.  Some will even work outside in the garden. I keep all of the following materials and ingredients handy in my plant pantry, along with a few clean spray bottles, for plant emergencies.  They happen more often than you'd think!

Management Method	Who/What it Manages	How to DIY
Horticultural (Insecticidal) Soap	Fungus Gnats, Whiteflies, Mealybugs, Aphids, Spider Mites (soft bodied insects)	Using original Dawn brand or Liquid Joy liquid soap only (nothing with additional power or chemicals): Combine 1 cup of vegetable oil with 1tbs liquid soap.  Mix well. Dilute the mixture by combining 2tsps of the oil/soap solution per 1 cup warm (filtered) water and put into a spray bottle.  Mix only what you’ll use in that day.  Do not store. Spray leaves above and below.  Shade for 24 hours after treatment to prevent burn.  ! Commercial soap sprays are effective and if you read the label, you can find non-chemical based sprays that are premixed and have a longer shelf life.
Yellow “Sticky Traps”	Whitefly, aphids, thrips, leafhoppers, moths, fruit flies, fungus gnats	Use yellow poster board or color an index card with yellow marker.  Cut into 1”x3” pieces.  Fold in half around a toothpick.  Secure (I use glue stick) Paint with honey or petroleum jelly on both sides of flag.  Push toothpick into soil.  Insects will stick and die.  Replace when there’s more full space than empty space on card.
Bury Garlic Bulbs	Burying a piece of Mother Nature’s natural insect repellent!  Burying garlic, is a Farmer’s Almanac-style trick to eradicate pests from houseplants.  Garlic is a natural repellent to large numbers of soil & leaf loving pests.  Too many to list.	Using one clove of garlic per pot, bury the clove into the soil about halfway.  If garlic begins to sprout, pull and transplant in garden then replace or allow to grow, trimming back the green shoots.  Replace monthly for best effects.  You can use the garlic clove with or without the skin.
Apple Cider Vinegar Trap	Fruit flies, fungus gnats	In a small container (I use a half-pint jar) fill with apple cider vinegar, cover tightly with plastic wrap and secure (I screw the jar rim over the plastic wrap but you can use rubber bands or tape)  Poke small holes in top of plastic wrap and place near the most insect activity.  Insects get in but can’t get out.  Replace every 2 weeks, every 1 week in humid summer weather.
Touch with Rubbing Alcohol (some say rubbing with a banana peel works too, but I’ve never tried it!)	Spider Mites, aphids	Dip a cotton ball or swab into a small dish of rubbing alcohol and lightly rub directly along plant stem and undersides of leaves where you see mite activity. Larger Scale Wash: Dip cloth into rubbing alcohol and lightly rub the entire plant.  You can dilute with water for very delicate plants. DO NOT NEED MUCH!  Lightly coat surface.  Do not pour or create dripping.  Shade for 24 hours after treatment.
Submerge, Rinse & Repot (The old college try)	A last ditch effort to rescue a plant from any pest, roots to tip of stem.	If a plant is completely infested, pulling the plant from the pot and shaking off all excess soil and submerging the entire plant in room temperature water for up to 15 minutes will send many of the pests looking for higher ground and they will “float” away.  Don’t be afraid to gently wipe the stems and corners to “bathe” the plant. Follow with a good rinsing and wiping of leaves then repot in clean potting mix. Follow up with a preventative treatment to keep potential eggs or stragglers from creating a new brood.
Removal and Disposal (The last resort)	Any Pest	Sometimes the insects win, and in order to save the rest of your collection, a badly infected houseplant with severe damage that has not responded to your methods for management should be discarded (not in your compost bin where they can multiply).

LOOKING FOR MORE INFORMATION?

Philadelphia Master Gardeners Horticultural Hotline ONLINE information: 

The Horticulture Hotline (HortLine) of the Penn State Extension Philadelphia Master Gardeners is a free service for residents of Philadelphia. Master Gardeners are ready to answer questions pertaining to: selecting vegetables, ornamental plants, pesticides, soil, plant and pest identification, pruning, compost, mulch, insect control, plant diseases, canning garden produce, food safety, and more!  If we cannot answer the question ourselves we will refer it to the Penn State University Hotline.   To contact the Philadelphia HortLine Online:         
     E-mail PhiladelphiaExt@psu.edu with "Hortline" in the subject line. 
     Please give your question, name and contact phone number. Include photos!

 Penn State Extension Juniata County Publication about Houseplant Pest Management

http://extension.psu.edu/juniata/news/2013/houseplant-pest-management

Houseplant Growing Tips and Pest Management Home Remedies

http://m.almanac.com/content/houseplants-growing-tips

Organic Home Remedies for Pests from Organic Gardening Online

http://www.organicgardening.com/learn-and-grow/all-purpose-insect-pest-spray

Good Guide for Controlling Aphids on Houseplants

http://homeguides.sfgate.com/kill-aphids-houseplants-45168.html

Quick and Easy Resources for Growing Avocado Basics

http://www.californiaavocado.com/grow-your-own-avocado-tree#houseplant

Do you hate stinkbugs?

By Sandy Grimwade

Anyone who lives in this area has been bugged by stinkbugs. They creep into cracks in windows and doors, they incompetently zoom around lights, and when dead they give off a nasty smell. Why are we seeing these bugs in such large numbers over the past few years and how can we keep them out of our homes and gardens?

Brown marmorated stink bug adult
Copyright Steven Jacobs, Penn State University

When people talk about “Stink bugs” nowadays they are usually referring to the brown marmorated stink bug (Halyomorpha halys). Pennsylvania is the center of this stinkbug invasion -- they are a species native to China and east Asia that was first seen in Allentown in 1996. In only 16 years they have spread across the USA and have become a significant agricultural pest, damaging mostly fruit crops and spreading viral diseases. They also feed on ornamental plants though they do not do severe damage. There is a great series of slides on the Rutgers University web site showing the scary spread of the stink bug over the past several years. 

Contrary to legend, stink bugs do not bite people or animals --  their mouth parts are not designed for biting. However, they are not great fliers and they can smack into you, leaving a welt.

What can we do about them and should we, as home gardeners and home owners worry about them? They certainly can be a nuisance in the home, and we want to keep them out if we can. The best way to do this is do make sure that they are excluded from entering by blocking up cracks around windows, doors etc. Check around your home with a caulk gun and fill up any cracks or gaps you find.

Once they are in the house, again, it is old-fashioned mechanical methods that are best. My favorite technique is catch-and-flush using toilet tissue. If you squash them, vacuum them, or trash them they will start to smell. Another popular way of catching stink bugs is to flick them into a jar of water containing a little dishwashing soap. Soapy water is lethal to stink bugs and once you have a batch of dead bugs in a jar you can easily flush them. Although stinkbugs can be killed with insecticides, it is preferable not to use insecticides inside the house.

Scientists and entomologists are still working on the best ways to control stink bug infestations on crop plants and ornamentals. Apparently common insecticides are only moderately effective and there is evidence that the stinkbugs can become resistant to insecticides.  Finally, those little brown bombers are mobile so even if you kill them off in your garden, another batch of bugs will fly in from a non-treated area.

Penn State Extension has a fact sheet about stinkbugs, as do many other state extension services. There are also a number of websites of varying reliability and entertainment value about stinkbugs and their control (e.g. http://stopstinkbugs.com). Some people really hate stinkbugs.